Stressed sleeve splicing of insulated electrical conductors



Sept. 29, 1964 E. H. souTER 3,151,213

sTEEssED sLEEvE SPLICINGv oF INSULATED ELECTRICAL coNDucToRs Filed oct. 5, 1960 s sheets-sheet 1 ',1 lullin/1 j I Sept. 29, 1964 E. H, som-ER 3,151,213

sTREssED SLEEVE sPLIcING oF INsuLATED ELECTRICAL ooNDuoToRs Filed oct. 5, 1960 v s sheets-sheet 2 :Nm/rm 2 EUGENE H. Sou-rr-:R

BY W MQW FH/i755.

Sept 29, 1964 E. H. SQUTER 3,151,213

STRESSED SLEEVE SPLICING OF' INSULATED ELECTRICAL ONDUCTORS Filed Oct. 5. 1960 3 Sheets-f-Sheet 3 f 9:9 f/// Il////// f @Hum 7.61/ EN (.f- 72 '1" .Il

Q gl "9 /8/09 2/ IN1/Ewan 2 EueaNe H. SouTER United States Patent ice Filed Oct. 5, 1960, Ser. No. 60,674 9 Claims. (Cl. 174-84) In the telephone industry cable splicing is an important consideration. Because of the millions or even billions of wire connections or splices which must be made, economy is important. Heretofore it has vbeen necessary to balance the importance of economy and the need for dependability, depending upon the class of service. In long distance, or toll cables, and often in trunk cables between exchanges, it has been common practice to twist and solder all connections to thus ensure minimum electrical resistance. In less critical circuits, such as -used for subscriber telephones, it has been common to rely upon unsoldered twisted connections. Soldered connections are expensive. Twisted connections, although amazingly dependable, do sometimes give trouble in the form of noisy or open circuits. Telephone engineering is constantly being improved. One such improvement employs much lower voltage on the telephone circuit. Many telephone engineers doubt that the simple twisted connection or joint will be adequate in the future even for use in subscriber telephone circuits. When any one of the many splices in the circuits connected to subscribers is poor, the service is inadequate. When an open splice develops, an entire pair of wires from a central station to the subscribers take-off location may be abandoned because it does not pay to search out such trouble in a long cable and open the cable to repair it.

Considerable experimentation has been done with punched sleeve splicing. Foremost authorities on cable splicing had hoped that by inserting the two wires to be connected into a sleeve and punching or squeezing this sleeve to grip the Wires, a connection would be made which be sufficiently dependable to replace soldering, and be far more economical to produce than twisted wire connections. The hopes for economy were justified, but the hopes vfor dependability were not. After vast sums of money were spent, the project, at least as then constituted, was abandoned because too often loose connections developed.

The invention of the rpresent application provides the needed dependability for the sleeve type of splicing without any loss of economy, and perhaps with `even greater economy than contemplated in the abandoned project.

Anfirnportant contribution towards making success out of failure is in providing a type of fabrication of this sleeve-joint which leaves the electrical contact under stress when the tool is removed, the residual stress holding the connection permanently tight and electrically and mechanically strong throughout all manner of climatic temperature changes. With the formerly proposed punched sleeve method, the punching tool simply pressed a portion of the sleeve inwardly with great force to displace the pulp or paper insulation and deforrn the wires for metal to metal contact between wires and sleeve. It was assumed that such thorough deformation or coldflowing of the metal under great pressure, would ensure a good connection. However, the metal in the sleeve adjacent to that in contact with the wire, which had been cold-flowed, was not in a cold-owed condition, but due to being bent or stretched retained elasticity or residual stress which reacted after removal of the punch to tend to open the electrical joint, or connection, and in many instances it actually opened the joint completely. According to the present invention the metal of the sleeve which extends towards the wires is tucked with great force between the adjacent part of the sleeve and the wires 3,151,213 Patented Sept. 29, 19.64

so that instead of being stretched, it is placed under compression, causing the walls ofthe -sleeve to be sprung, or placed in a state of resilient tension, or stress tending to move the tucked-in Vportion of the sleeve, which is engaging the wires more tightly into engagement with the wires. In short, the residual stress pulls the Contact tight, instead of pulling away.

The Vcompression of the contacting `metal is accomplished in the illustrated form by shearing a tongue from the sleeve and bending this tongue in an arcuate path about the base or root of the tongue so that it moves viirst towards the wires, but at the end of its stroke is tucked with great force between the wires and the base of the tongue or the opposite wall of the sleeve.

An important advantage of this force-tucking method is that the arcuate movement of the tip` of the tongue scrapes the wires clean of insulation and of oxide so that the tongue reliably engages the clean bare wire.

Although considerable force is exerted by the .tongue on the wire in this f orce-tucking action, the wires are prevented from shifting in the sleeve during this operation by a balanced condition created by employing two fingers which are substantially alike and operate under the same conditions but move away from each other. The only resultant force on a Wire, besides pressure against it, is a harmless tendency to draw the wire taut between the tongues.

Preferably the necessary force is provided by power, such as compressed gas, although a hand-power tool has been designed. In the illustrated form of the invention, the sleeve detorming mechanism is carried by a handle which for the most part lits within the hand and includes a ypneumatic cylinder for powering the joint fabricating mechanism and a trigger for controlling the pneumatic cylinder.

According to the prior project mentioned, the splicing sleeve was preassembled within a plastic insulating jacket. The punching left noticeable holes in the jacket. The joint fabricating mechanism here indicated cuts neatly through the insulating jacket, and in spite of the extensive movement of the parts which force-tuck the tongues in, leaves the jacket in such `condition that after a few seconds of recovery of the plastic material, there is again no bare metal exposed. With close scrutiny, clean cuts in the jacket .can be observed, but the facing edge of the cuts seem to have drawn together to such extent that there is not the slightest danger that the metal sleeves will inadvertently come in Contact with one another as they are packed closely vtogether in the course of closing up the cable.

It the assembly is in a grease-packed condition before splicing, I have found that there is a self-,healing action after splicing. The splice .can even be immersed in water without causing a cross connection to the water, and corrosive atmosphere is also excluded. The grease seals oi the cuts in the jacket, and coats or enwraps all exposed surfaces of the copper.

Additional objects and advantages of the invention will be apparent from the following description and from the drawings.

Designation of Figures FIG. 1 is a side elevation of the apparatus of this invention in the form at present preferred.

FIG. 2 is a vertical longitudinal sectional View taken through the structure illustrated in FIG. l, except that no attempt is made to show details of the joint fabricating mechanism which would be on too small a scale for ready understanding in this view.

FIG. 3 is a view of the structure shown in FIGS. 1 and 2 looking at it from the bottom as shown in those views, or in other words, from the trigger side.

anemie FIG. 4- is a sectional view showing the completed stressed joint splice, which is itself an important aspect of the present invention.

FIG. 4A is a similar View of a similar splice, which is grease-packed.

FIGS. 5 to ll show details of the joint fabricating mechanism on a much larger scale than it would be possible in FIGS. l and 2, although it is to be understood that this mechanism is normally located in the small boX- like chamber shown at the upper left portion of FIGS. l and 2.

- FIG. 5 shows mainly a side view of the deforming mechanism, with portions broken away to a sectional view, generally as this mechanism would be seen in FIG. 2 if there shown.

FIG. 6 is a bottom view of 'the fabricating mechanism of FIG. 5.

FIG. 7 is a top View partly in section of the fabricating mechanism of FIG. 5 showing also a portion of the surrounding housing of the hand tool in which the mechanism is located.

FIG. 8 is a transverse sectional view taken approximately along the line 8 8 of FIG. 5.

FIG. 9 is a view corresponding to FIG. 6 but showing the actuating slide in its fully actuated position, and the working parts moved by it, also in their fully actuated positions.

FIG. l() is a view showing tde lirst step of the joint forming operation, before the tucking lingers have begun to move.

FIG. ll is a View similar to FIG. l0 but showing the final position of the tucking fingers.

FIG. l2 is a transverse sectional View taken approximately along the broken line lZ--IZ of FIG. ll.

General' Description and Operation Although the following disclosure offered for public dissemination is detailed to ensure adequacy and aid understanding, this is not intended to prejudice that purpose of a patent which is to cover each new inventive concept therein no matter how others may later disguise it by variations in form or additions or further improvements. The claims at t Ae end hereof are intended as the chief aid toward this purpose, as it is these that meet the requirement of pointing out the parts, improvements, or combinations in which the inventive concepts are found.

The splicing tool comprisinfy one aspect of the invention is shown as a small hand tool Il, the central portion of which is of a size to be 1aeld readily in the hand with a finger on the trigger I2 and with the operating head i3 projecting forwardly of the hand. rIhe power cylinder I4 is shown projecting rearwardly of the hand so that it may have a diameter large enough to require only moderate pneumatic pressure. Another version, for still lower pressure, has been designed with tandem pistons.

The operating head I3 has an aperture I6 into which may be inserted the splicing assembly. With reference to FIG. 4, this splicing assembly may include an insulating jacket 17, preferably formed of a resilient plastic material such as polyethylene and sealed at one end. A plastic which recovers as previously indicated is preferred. Within this jacket is located a sleeve 13 which in its initial form would be simply a cylindrical sleeve or tube preferably slightly flared at its outer or receiving end 19 to facilitate the entry of the Wires 2l. The flare also ensures the retention of the sleeve within the jacket 17 since the jacket is snug-fitting enough to be stretched slightly by the flared end portion 19. Probably the preferred method of operation will involve slipping the wires 2l into the jacketed sleeve 13 before the assembly is inserted into the aperture i6.

When the trigger 12 is then pressed, air or gas is admitted to cylinder I4 to shift the actuating slide 2S to the right, thereby operating the fabricating mechanism to eform the sleeve to the condition approximately as shown in FIG. 4. This will be described more in detail later but it may here be noted that a pair of tongues 2d has been sheared from the side of the metal tube and bent through an arcuate movement until they are tucked between the roots of the tongues and the wires ZI, the tongues 24 being under compression from the surrounding tube, which is thereby stressed and deflected to create residual stress, so that the blunt ends of the tongues 24 are permanently held rmly under considerable pressure against the wires 2l., at points where the wires have been stripped clean of insulation by the leading edge of the tongues.

If sealing from water is desired, a sealing material 25, such as low-viscosity silicone grease, may be provided. Conveniently, the jacket 17 may be partially lled with it before the wires are inserted, preferably before inserting sleeve I8.

Gun or Poweriltg Unit In a sense, it might be said to make no difference by what means the fabricating components are operated, or if actuating slide 23 is used, by what means is operated. Perhaps an explanation or" one form of power unit or gun for actuating it will nevertheless be helpful at this point.

As seen in FIG. 2, a trigger l2 is pivoted on a pin 2d and when pulled thrusts valve rod or plunger 27 toward the right. The trigger I2 transmits this thrust through a pivoted lever 28 which carries a friction reducing roller 29. As the trigger I2 reaches the end of its movement a latch lever .31 biased by spring 32 engages notch 33 in trigger l2 to lock the trigger I2 in its actuated position and thereby hold the valve plunger 27 to the right.

Com `ressed air (or other gas such as nitrogen or carbon dioxide) is supplied by a hose 36 (FIG. l) through a fitting 37. With the parts in the positions shown in FIG. 2, the compressed gas or air cannot go anywhere. It is conned to the annular passage 38 surrounding a reduced portion of valve rod 27 by valving section 39 which in this normal position lies within O-ring seal 4l.. In the opposite direction, O-ring d@ seals rod When the trigger I2 is actuated, valving section 39 shifts to lie within (lt-ring seal d2, and the annular passage 33 will be shifted to the right to communicate with drilled passage 43 which opens into piston chamber 44, on the left side of the piston Kid. Piston do may be sealed with an O-ring seal 47. The compressed air or gas thus moves the piston 45 to the right, drawing the piston rod i3 also to the right and this in turn draws the actuating slide 23 to the right. Piston rod 43 is also sealed by lCt-ring seal 5t?. 'I' he operations accomplished by the slide 23 in fabricating the electric joint are described under the next heading. As the slide 23 reaches the end of its stroke, a lug 5l strikes the heel S2 of latch lever 3l releasing trigger I2 so that it returns to the position shown in FIG. 2. This permits return of the valve rod 2.7 to the left, under influence of spring 53. Most of the length of spring 5S is housed Within the hollow valve rod 27, but its right-hand end extends into and bears against retaining cup 5d, which is held in place by set screw 515.

When valve rod 27 shifts to the left, the valving section 39 moves from within O-ring l2 to Within O-ring 4l.. This shuts olf the compressed air from passage 43 and instead connects passage i3 with the atmosphere. This. may be through a restricted bore 5S by which the speed. of the return movement of the parts may be controlled.. As air escapes from the left side of piston 45, spring 59 returns the piston towards the left to the position shown in FIG. 2. In order that the spring 59 may have adequate. length, the piston d6 is provided with a thimblelike extension 6I into which the spring 59 extends. As the pis-- ton lo moves to the left, the actuating slide 23 also moves` to the left so that all parts are returned to their starting positions shown in FIG. 2 and, as we will now see, in FIG. 6.

Stressed Joint Fabricating Mechanism The best views of actuating slide 23 and of the parts which it engages are FIGS. 6 and 9, which show the parts respectively in their normal and actuated positions. There are two integrated steps of the fabricating operation, both powered by the actuating slide 23. The first operating step might be called the entry of the tucking fingers 63. At the end of this step, the condition is as seen in FIG. l0. However, this is accomplished not by moving the tucking elements .or lingers 63 but by thrusting the splicing assembly 64 onto them by moving a sliding die 66 towards the ngers 63.

The second step of the operation is the turning of the tucking lingers 63 to the position s hown in FIG. ll for shearing the connecting lingers, tongues, and driving them to their final position.

Sliding Jaw Operation FIG. 5 shows the sliding jaw 66 in its retracted position, the chamber 67 which receives the splicing assembly being thereby enlarged. When the splicing assembly has been inserted in chamber 67 and the trigger 12 of FIG. 2 pressed, the actuating slide 23 is moved to the right under power. The manner in which this accomplishes the first operating step of moving the jaw 66 to the right is by turning a pair of cranks. Each crank includes a crank shaft 69 which has a bearing fit with frame block 71 of the fabricating mechanism. As seen best in FIG. 6, each crank shaft 69 carries at its lower end a crank arm 72 having a downwardly extending crank pin 73. This pin preferably carries a friction reducing roller 74 and in any event the pin 73 or its roller 74 rides in an L-shaped slot 76 of slide 23, there being one for each of the crank pins 73. it is apparent from FIG. 6 that as the actuating slide 2 3 is shifted to the right, the two crank arms 72 and their crank shafts 69 will be turned until the pins 73 are aligned with the elongated idle portions of slot 76. Thus the cranks will be rotated approximately 9() degrees and locked in that position during the balance of the travel of slide 23.

As seen best in FIG. 8, each of the crank shafts 69 Vhas formed at its upper end a crank arm 77. Each crank arm 77 has an upwardly extending crank pin 78 preferably provided with a fraction reducing roller 79. It is apparent from FIG. 7 that as the crank shafts 69 are rotated from the normal position shown in FIG. 7, the crank pins 78 will thrust the slotted thrust plate 81 to the right. The s lots 82 in this thrust plate are long enough to allow the crank pins 78 to move the distance inward required by the amount of turning of crank shafts l69 induced by the slots 76 in FIG. 6. The thrust plate 3 1 may be regarded as merely a portion of the sliding jaw 66, which moves right and left with thrust plate 81. Thus the turning of the cranks 68 by the first part of the movement of slide 2 3 thrusts the sliding .jaw 66 to the right from the position seen in FIG. 7 to the position seen in FIG. l0. This movement thrusts the splicing assembly 64 against the tucking fingers 63 so that these fingers cut very short slits crosswise in plastic insulation jackets 17 through which they enter and depress the copper sleeve 18 approximately as seen in FIG. l0. This depressing action is performed with high precision due to the high precision with which jaw 6 6 is moved.

The sliding jaw 66 can alternatively be operated by toggle linkage. The toggle links are nearly straightened out when the sliding jaw is in its advanced position so as to hold the jaw precisely without requiring much application o f force from the actuating slide which bears on the knee joint of the toggle linkage. This construction has been found satisfactory, but it was not as compact as the illustrated form. Operators sometimes like to hold two splicing assemblies in their hand, and the illus- -trated form leaves more ,clearance for the second assembly to lie beside the tool while the first is in `the tool.

-T ucking Finger Construction and Operation After the sliding jaw 66 has been advanced to the position lshown in FIG. 10, so that the lingers 63 have pressed this sleeve 18 to the extent substantially as there shown, further movement of actuating slide 2 3 to the right will turn the tucking fingers 63 from the position shown in FIG. 10 to the position shown Vin FiG. 1l. This is accomplished by slots 8 6 of slide 23 and more specically by camming surfaces 87 thereof. Thus after approximately the first half of the movement of lthe actuating slide 23 to the right, during which crank pins 8,8 are unaifected, the camming surfaces ,S7 will strike crank pins 88 or the friction reducing rollers 89 thereof, thereby moving the crank pins 88 areuately toward one another. These crank pins extend downwardly from crank arms 91 which are thus turned, correspondingly turning .crank shafts 92 and correspondingly .turn the tucking `lingers 63 formed on Ithe heads of crank shafts 9 2. The tucking lingers 63 are thus moved 4from the FIG. l0 position to the FIG. 1l position. The camming surfaces of slide 23 can be shaped to v ary the force as`needed.

Slots 86 are provided with parallel terminal portions 93, and slots 76 with suliicient excess length, so that after the tucking fingers 63 have completed their work, actuating slide 23 may move enough further for its lug l51 to engage, and drive slightly to the right, heel 52 of trigger latch 31. This unlocks trigger 1 2 and permits it to return from its operating to normal position, thu-s effecting Yreturn movement of the parts. Thus, as the actuating slide 23 then moves to the left, the cam surface 94 will give a reverse actuation to crank pins 88, crank arms A91, crank shafts 92 and tucking fingers 63 to restore them to their normal positions shownin FIGS. 6 and 7, and slots 76 similarly return jaw 66.

The assembly of this joint fabricating mechanism is quite simple. The top block 9,6 being off, the two crank shafts 69 and the two crank shafts 92 are dropped into place `in frame block 7 1, with their heads turned to the positions `shown in FIG. 7. The rollers 7 9 are slipped on the crank pins 78. Positioning tooth 106 is placed in position and pin inserted. The sliding jaw 6 6 is set in place and moved to the left. The thrust plate 81 is .then slipped on, and the desired spacers 83 and 84 inserted, and then the top block 96 is applied, turned upside down, and secured by screws 85. The four crank arms are applied and the friction reducing rollers slipped on the four crank pins and may be temporarily held on with stiff cup grease to facilitate final assembly. The actuating slide V.23 may now be laid on, with the crank pins extending into the various slots.

The foregoing assembly is then applied to `the gun or powering unit before the hood 98 thereof has been applied. The piston rod 48 may be retracted to permit this, or the piston and this rod may be inserted just after this step. A connecting pin 99 is dropped into place connecting the actuating slide Z3 with thepiston rod 48. The hood 98 is then applied and secured with screws 100.

The assembly of the gun or power unit, which except for insertion of the piston would usually take place prior to the foregoing, is believed to be suiiiciently evident for the most part from the drawings, especially FIG. 2. One detail that might not be apparent is that after the piston assembly 4 6 is inserted, spring 59 is inserted while it is held 'compressed with cylinder head 101, pressed in a little further than its normal position, a split'snap ring 102 is sprung into place. Then the pressure is removed from the outside of cylinder head 101 and spring 59 presses it into engagement with the snap ring 102. Cover plate 103, attached by a screw, is more decorative than necessary.

Positioning Tooth At present it is preferred that a positioning tooth 106 be provided as shown in FIG. 7. This presses into the sleeve 18 at the same time as the tucking iingers 63, though not so far, both entries being accomplished by movement of the sliding jaw 6F. The positioning tooth 106 prevents unintended movement of the sleeve 18. Conceivably experience may show tha-t the positioning tooth 106 is not needed, in which event it may be omitted. The chief advantage of omitting it, however, is in requiring slightly less power for the iirst step of the sliding of sliding jaw 66, and so there is no great hurry about determining whether tooth Midis necessary. It may be very necessary, for conceivably some nonuniformities of the sleeves or the change in resistance as one of the tucking lingers 63 breaks through could cause considerable impairment of the operation by shifting the sleeve 18.

Joint Fabrication Considerations It is at present deemed important to drive the sleeve 1S during the first operating step against the tucking fingers 63 by straight line motion and to locate and lock it there with high precision in order that accurate relationship may be established between the axis about which the iingers rotate and the sleeve. The arcuate movement of the tucking lingers 63 accomplishes a similar arcuate movement of the tongues 24. This initially performs a wiping and scraping operation on the wire to remove the wire insulation, scrape oxide from its surface, and finally to ilatten adjacent sides of wires for large Contact area. Ultimate contact is not between the leading edge of the tongue 24 and the wire but between a portion of the end of the tongue 24 which is rearward trom its leadu ing surface; hence, even if it can be conceived that a fibre might be caught under the leading edge and wiped along the wire, it may be expected that a large clean contact will be made between the wire and the blunt trailing portion of the tongue 24. Furthermore, the pressure is so great that the wire is ilattened or reshaped to it the tongue and have a large area of contact with it due to the fact that the root of the tongue and the tip thereof along with a portion of the wire and an opposing wall portion of the sleeve are all substantially in a straight line perpendicular to the length of the wire. Thus, there is produced a joint of minimum resistance. In any event, thousands of tests have been made without a single failure to obtain a good contact.

Looking at HG. 1l, it is apparent that the length of the tongue 24 as shown there is considerably less than the length of the dotted line wall from which it has been sheared. This may be essential and results from the geometry of design, the nature of the metal in the sleeve and the force applied to produce the joint. ln a given sleeve, the exact nal length of this shortened tongue may vary depending on the size of `the wire. Longer tongues will result when small wires are spliced; and when larger wires are spliced, there is less room for the length of the tongues, so tucking in the tongues may be expected to shorten them and to require greater torce. With the larger wires the greater tucking force will be advantageous because it will produce greater pressure of the ends of the iingers against the wires. The greater pressure results in a larger contact area. The greater force is evidenced by a shorter radius at the root it??? of the nger and a slight bulge of excess metal. lt is of greatest importance that, as a result of the tucking force, the walls of the metal sleeve are sprung, thus producing residual stress, using the elasticity of the metal, so that the sleeve acts as a very stiftC spring which forever maintains a grip on the wires to hold the joint securely tight regardless of any dimensional changes that may take place in the joint as the result of temperature changes or other conditions. lt will be observed that recesses il@ are provided in the sliding jaw 66. There is likewise recessed area at the diametrically opposite position, partly in each of the frame block and cover block, adjacent the root idd to permit the elastic swelling to occur. This is also a safeguard against excessive tucking forces, and thus helps to accommodate a wide range of Wire sizes.

CTL

rihe wires are held with extreme firmness in this manner. Frequently tension test has broken the wire elsewhere rather than pulling it from the clamped position between the tongue 24 and the opposite portion of the sleeve. Experience may show that there is some advantage, perhaps in accommodating a wider range of wire sizes in having the inner tucking linger (at the left in FlG. ll) slightly longer than the other. Even without that, the great force holding a good contact is indicated by the fact that the wires are considerably spread out and shaped to conform to the tip of the tongues 213. Careful filing into the resulting splice reveals structure about as seen in FiG. 4 although that ligure exaggerates the swelling of sleeve i8 at the bottom. Filing in the opposite direction indicates that the reduced wire thickness seen in 4 is in fact a spreading out rather than a slicing oir" of the copper of the wire. Thus it appears that the intention to have the wires wiped by tongues 24 of the same metal as that of the wires, rather than by the tucking fingers, is achieved. rThe leadinT edge of the tongue 24 is found to be quite blunt. Nevertheless the insulation, at least the three types commonly used in telephone cables (pulp, paper and plastic), is invariably scraped completely away to provide a very satisfactory contact. The electrical resistance through a large number of such contacts in series has proved to be as low as the resistance of an equal number of soldered twisted contacts.

As seen in PEG. l2, the tucliing ngers 63 are preferably wide enough at side shoulders il@ so that they substantially occupy the inside diameter of the sleeve 18. Tongues will likewise have shoulders lll to center tongues in the sleeve. The wires will be reliably pressed generally toward the far side of sleeve 13 by tongues and held there. The leading edge of each tucking hoger 63 is transversely arcuate as seen in FG. l2, so that the tips of tuck-in tongues 24 will be similarly shaped. rlhe arc should be such as to provide substantially uniform spacing between the tongue and the far wall of sleeve id.

rihe reason for forming the tip of the tongue Zd of arcuate contour is to provide substantially parallel or uniformly spaced surfaces gripping the wires between the end of the tongue the opposite wall of the sleeve. T his in turn has two advantages:

(l) The forging of the wires will be about the same, wherever the wires may locate themselves around the insido radius; and,

(2) Of much greater importance, no wire can, in time, shift to a position where the space is larger with resultant inadequate gripping of the wire. Indeed, any surfa es which do not permit shifting may be deemed spaced with substantial uniformity.

lf sleeves 1S square in cross section were used, tips of the finger should be flat, to cut a tongue which would be substantially uniformly spaced from the far wall of the `square tube.

A taper, or draft, of lingers o3 facilitate the return movement of the fingers and ensure easy removal of the fabricated joint after the operation is completed. In case the fingers are not withdrawn clear of the sleeve they will be quite loose in it.

rl`he location of fingers 63 close to their rotational axis (the axis of crank shaft 92) is advantageous. Together with their entry into the sleeve before they start rotation, this short radius permits the use of the same short sleeves planned for the prior project mentioned. Also, the amount of scraping along the wire appears to be about ideal.

As indicated in FIG. 4A the splice of FIG. 4 may be packed with a self-healing grease which seals against entry of water in which the splice may be immersed. Although the grease could be injected after splicing, an added advantage of this invention is that if the jacket and sleeve are furnished in a grease-packed condition, or if the sleeve is irst filled with a proper quantity of grease, and then the sleeve inserted until immersed in the grease.

the grease redistributes itself after splicing to provide the desired seal. After the wires are thrust in or inserted, the assembly is inserted in the tool and the splice made just as already described. The grease flows into, and apparently iills the cavity 95, probably as or just after the tucking fingers 63 are withdrawn. The lack of any evident escape of the grease or of any apparent displacement of it toward the openend of jacket 17 indicates that the thrust of the tucking lingers, as they enter displaces the grease to expand or deforrn the jacket 17. As the fingers are withdrawn, forces such as the recovery of the jacket then redistribute the grease causing flow into cavity 95. This redistribution may be aided by the fact that the lingers 63 are so shaped as to maintain a substantially sealing tit with the holes they cut in the jacket. To this end the periphery of the fingers are concentric with their rotational axis.

As has been proposed heretofore (when use of the splice of this invention was not contemplated), the grease also seals the open end of sleeve 17, so that no metal is exposed to any surrounding water or corrosive -atmosphere.

The grease should be soft enough to iow easily, and should have sufficient viscosity, with suiiicient stability thereof not to run out at any temperature to be normally encountered. Silicone bearing grease of medium viscosity (about the consistency of Vaseline petroleum jelly at 70 F.) is apparently ideal. Other sealing materials which flow easily but will not liow 4out by gravity may also be suitable.

Although the drawings are approximately to scale, and skilled designers could choose their own dimensions according to principles here disclosed, it may be helpful to note the following dimensions which have been found satisfactory. With the jaw 66 advanced, the sleeve is in a position such that the tips of tucking ngers 63 are just a little short of the sleeve axis. With a sleeve of about .092 I.D. and .152 O.D., the tucking lingers, before being turned, reach to about .013" short of the axis of the sleeve (ignoring any iiattening that may occur in the first step) and have radii of about .216". The tip portion of the leading edge of each tucking finger forms an arc of a radius of about .040 for small wires and slightly less for larger wires. The radius should provide room for as many wires as may be spliced in one splice and may extend as far as about 150-170. If the tongue would exert too great a forging force, particularly with small wires in mind, the sides of the fingers may be notched to form a narrower tongue root. For easy re- -moval the sides of fingers 63 may be ground, for example, to planes which, in the extended positions of the fingers, cause the fingers to thicken upwardly from about %2" at the shoulder 110 on the sides of the tip to a line 112 (FIG. 11) extending horizontally rearwardly from the top of the face.

Other triggering systems than that illustrated can of course be used. In fact a feature not illustrated but now contemplated as preferred, is to have the triggering action self-completed on initiation, so that there is no possibility of a failure induced by not pulling the trigger far enough to lock. To this end, the return movement of actuator slide 23 could cock a hammer or thrust lever which when released by a slight trigger movement would thrust thev valve rod 27 all ofthe way to the right. Likewise, spring 59 will probably be omitted and pneumatic pressure used in both directions with a smaller cylinder diameter or lower pressure. Valve spring 53 may be omitted and a snapaction mechanism used to snap the valve from one extreme position to the other, which would also permit a simplified self-completing trigger action.

Although copper wires have been mentioned, aluminum wires may, of course, be used. In that event an aluminum sleeve is preferred.

From the foregoing it will be seen that according to the illustrated form of the present invention a strip of metal, or tongue, is sheared at one end and two sides from a side of the sleeve and, remaining `attached to the sleeve at the other end, this tongue, is then moved radially through an arc on an axis at its unsheared end. This tongue is so dimensioned as to length that it would about touch the inside of the wall of the opposite side of the sleeve if no wires were in the sleeve when it is driven to its iinal position substantially perpendicular to the axis of the sleeve. When insulated wires are present in the sleeve for making an electrical and mechanical joint, four very important things happen as the tongue is tucked in by substantial force:

(l) As the tongue is driven through its arc of travel, its end swings against the wires removing insulation and scraping it back out of the way, and also forges the wires on one side to provide a large contact area with the tongue.

(2) The blunt arcuate end of the freshly sheared tongue is by this radial motion iinally brought to bear under heavy permanent pressure against the concurrently forged conforming surfaces of Ithe wires to thus produce a joint having minimum electrical resistance.1

(3) The forceful tucking of the tongue necessarily caused the sleeve or at least some parts thereof such as the opposite Wall supporting the wires, to be sprung outwardly or intinitesimally expanded. The extent may depend upon the sizes of wires .being joined. In any event, this section of the sleeve is placed under permanent stress in the form of elastic tension. This causes the electric contact to be held permanently under high pressure, thereby maintaining a lirrn, corrosion free, low resistance joint regardless of dimensional changes resulting from temperature changes or other causes to be encountered in use. Perhaps the elastic tension most easily visualized is that of the sleeve Wall portions opposite the tongues. As each tongue presses the wires forcefully against the far wall that Wall portion inevitably is bulged (elastically stretched) a minute amount.

(4) The heavy, springlike preload imposed on the conductors affords the joint mechanical strength substantially equal to the tensile strength of the copper wire itself, which is still another very great advantage over the previously attempted method of telephone cable punched sleeve splicing.

In case a greater length of possible resilient action is found necessary, it may be provided by suitable changes. According to one such change, the front face of each tucking finger 63 may be shaped to provide a forwardly extending nose about midway between its tip 4 and base, or a little closer to its tip, so that the tongue has a slight hump. Any resilient tendency of the hump to straighten out will give added length of resilient `action to take up any slack which might otherwise develop, for example, under extreme temperature conditions. According to another change, the wall thickness of the sleeve can be reduced. Of course, also the temper of the sleeve can be varied.

This application is a continuation in part of rny prior application, Serial Number 856,130, filed November 30, 1959.

I claim:

1. An electrical connection including a plurality of insulated Wires, a copper sleeve having a body surrounding the wires and an insulating jacket surrounding the sleeve, characterized by the feature that the sleeve has two tongues cut from it in opposite directions and originally extending toward one another from their respective roots, bent away from each other and tucked forcefully between the body of the sleeve and the wires, the sleeve 1Examination indicates that the pressure also presses the wires through the insulation (plastic or paper) to contact the far wall of the sleeve.

having wall portions against which the Wires are directly squeezed by the tongues, whereby stresses are developed to maintain the wires elastically under compression, the root of each tongue, the tip of the tongue, a portion of the wire and an opposing wall portion of the sleeve all being substantially in a straight line in a plane perpendicular to the length of the wire.

2. An electrical connection including a wire and a conductive sleeve having a body surrounding the wire, characterized by the feature that the sleeve has a tongue cut from it bent inwardly and tucked forcefully between the body of the sleeve and the wire, and having a length sufiicient to stretch the sleeve elastically and thereby remain under compression; and an elastic insulating jacket packed with an insulating sealant of the consistency of soft grease in which the sleeve is fully immersed and which seals in the area enteredrby the splicing tool which tucked in the tongues, to prevent contact of the metal with any surrounding water.

3. An electrical connection including a wire and a conductive sleeve having a body surrounding the wire, characterized by the feature that the sleeve has a tongue out from it bent inwardly and tucked forcefully between the body of the sleeve and the wire, the sleeve having a wall portion against which the wire is directly squeezed by the tongue, whereby stresses are developed to maintain the wire elastically under compression, the root of the tongue, the tip of the tongue, a portion of the wire and an opposing wall portion of the sleeve all being substantially in a straight line in a plane perpendicular to the length of the wire.

4. An electrical connection including yan insulated wire and a conductive sleeve surrounding the wire, characterized by the feature that the sleeve has a tongue out from it and originally extending lengthwise of the sleeve, which has been tucked forcefully between its root and the wire, with insulation on the wire thereby scraped away, the sleeve having a wall portion against which the wire is directly'squeezed by the tongue, said sleeve having stresses developed by said tucking to maintain the wire elastically under compression.

5. An electrical connection including a wire and a conductive sleeve having a body surrounding the wire, characterized by the feature that the sleeve has a portion bent inwardly and tucked forcefully between the body of the sleeve and the wire, and having -a dimension to stretch the sleeve elastically and thereby remain under compression, the sleeve having a wall portion against which the wire is directly squeezed by the tucked-in por` tion, opposed wall portions of the sleeve on opposite sides of the wire, a portion of the wire and the tucked-in portion all being substantially in a straight line in a plane perpendicular to the length of the wire.

6. An electrical connection including a wire and a conductive sleeve having a body surrounding the wire, f

characterized by the feature that the sleeve has a tongue cut from it bent inwardly and tucked forcefully between the body of the sleeve and the wire, and having a length suicient to stretch the sleeve elastically and thereby remain under compression, the sleeve having a wall portion against which the Wire is directly squeezed by the tongue, and the tip of the tongue being substantially uniformly spaced from the opposing wall of the sleeve, the root of the tongue, the tip of the tongue, a portion of the anais 12 wire and an opposing wall portion of the sleeve all being substantially in a straight line in a plane perpendicular to the length of the wire.

7. An electrical connection including a wire and a conductive sleeve having a body surrounding the wire, characterized by the feature that the sleeve has a tongue cut from it bent inwardly and tucked forcefully between the body of the sleeve and the wire, and having a length sufficient to stretch the sleeve elastically and thereby renain under compression, the sleeve having a wall portion against which the wire is directly squeezed by the tongue, and the tip of the tongue being substantially uniformly spaced from the opposing wall of the sleeve, the root of the tongue, the tip of the tongue, a portion of the wire and an opposing Wall portion of the sleeve all being substantially in a straight line in a plane perpendicular to the length of the wire and an insulating jacket of plastic material enclosing the sleeve and having recovery characteristics whereby any hole formed by a tool in tucking the tongue in the sleeve closes itself.

8. An electrical connection including a wire and a conductive sleeve having a body surrounding the wire, characterized by the feature that the sleeve has a tongue cut from it bent inwardly and tucked forcefully between the body of the sleeve and the wire, and having a length `sufcient to stretch the sleeve elastically and thereby remain under compression; the sleeve having a wall portion against which the Wire is directly squeezed by the tongue; the root of the tongue, the tip of the tongue, a portion of the wire and an opposing wall portion of the sleeve and being substantially in a straight line in a plane perpendicular to the length of the wire and an elastic insulating jacket packed enclosing the sleeve `and with grease which seals in the area entered by the splicing tool which tucked in the tongues, to prevent contact of the metal with any surrounding water.

9. An electrical connection including a conductive sleeve, conductor means within the sleeve and extending therefrom to form part of an electric circuit, a pressure member within the sleeve and which, with the conductor means, bridges between directly opposite wall portions of the sleeve, the pressure member being in a compressed condition corresponding to having been forcefully pressed into its position and having a dimension transverse of the sleeve larger than the corresponding internal dimension of the sleeve in relaxed condition, whereby the sleeve remains elastically stretched by said pressure member and said conductor means, the opposite wall portions of the sleeve, the pressure member and a portion of the conductor means all being substantially in a straight line in a plane perpendicular to the length of the sleeve.

References Cited in the tile of this patent UNTED STATES PATENTS 2,370,725 Gordon Mar. 6, 1945 2,684,093 Klinger iuly 20, 1954 2,783,442 Burnosky Feb. 26, 1957 2,820,843 Dreher lan. 2l, 1958 2,821,011 Saunders et al ian. 28, 1958 2,861,324 Klurnpp Nov, 25, 1958 2,872,505 Ustin Feb. 3, 1959 2,890,266 Bollrneier lune 9, 1959 2,927,150 Arnigh et al Mar. 1, 1960 2,952,174 Broske Sept. 13, 1960 UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent Neo 3,151,213 September 29, 1964 Eugene H. Soute1^ 1t ie hereby certified that errer appears in the ebeve numbered petent requiring correction and that the said Letters Patent should read as Corrected below.

Column l, line .39, after "which" insert would g-; column ll, line 35, for "out" read cut column l2, line 30, for "sleeve and" read sleeve all u@ Signed and sealed this l4th day of September 1965.,

(SEAL) Anest:

ERNEST W. SWIDER EDWARD J. BRENNER Attesting Officer Commissioner of Patents Patent Noc 3, 151, 213 September 29, 1964 Eugene Ha Souter It is hereby certified that err ent requiring correction and that th corrected below.

or appears in the above numbered pate said Letters Patent should read as Column 1 line 39 after "which" insert would 3 Column 11 line 35, for "out" read cut column 12, line 30, for "sleeve and" read sleeve al1 Signed and sealed this 14th day of September 1965e (SEAL) Attest:

ERNEST W. SWIDER EDWARD J. BRENNER Attesting Officer Commissioner of Patents 

4. AN ELECTRICAL CONNECTION INCLUDING AN INSULATED WIRE AND A CONDUCTIVE SLEEVE SURROUNDING THE WIRE, CHARACTERIZED BY THE FEATURE THAT THE SLEEVE HAS A TONGUE OUT FROM IT AND ORIGINALLY EXTENDING LENGTHWISE OF THE SLEEVE, WHICH HAS BEEN TUCKED FORCEFULLY BETWEEN ITS ROOT AND THE WIRE, WITH INSULATION ON THE WIRE THEREBY SCRAPED AWAY, THE SLEEVE HAVING A WALL PORTION AGAINST WHICH THE WIRE IS DIRECTLY SQUEEZED BY THE TONGUE, SAID SLEEVE HAVING STRESSES DEVELOPED BY SAID TUCKING TO MAINTAIN THE WIRE ELASTICALLY UNDER COMPRESSION. 